This application claims foreign priority of JP application 09-346202, filed Dec. 16, 1997.
The present invention relates to a pesticidal composition.
Japanese Laid-open patent No. sho-53-109945A and Japanese Examined patent No. sho-61-33001B disclose a method wherein a pesticidal composition fumigates to control pests. However, the methods disclosed in the said patents do not efficaciously control pests when a solid pesticidal ingredient is employed in the pesticidal composition.
Based on prior pest controlling methods, a pesticidal composition comprising of a solid pesticidal ingredient that has a low vaporization rate, is not available. A lower vaporization rate distributes a smaller dosage of the pesticidal ingredient and consequently procures an ineffective pest controlling performance.
The present invention relates to a pesticidal composition particularly against mites and cockroaches inhabiting an indoor environment. When the pesticidal composition is fumigated, a high amount of the pesticidal ingredient is released to control pests such as cockroaches and mites effectively. The present invention employs the pesticidal ingredient as a multiplicity of solid granules wherein the volume median diameter is 30 xcexcm or less.
The pesticidal ingredient utilized for the present invention is a solid at room temperature. The grain of the pesticidal ingredient powder has a volume median diameter of 30 xcexcm or lower, and generally the powder, the grain size of which is 3 to 30 xcexcm in volume median diameter, may be utilized. The employment of the pesticidal ingredients is generally not restricted, but a condition wherein 70% or more of the grain of the pesticidal ingredient powder have a diameter of 30 xcexcm or less is preferable. As used herein, the volume median diameter is the diameter wherein an equal total volume of grains with greater and lesser c grain diameters are present, when the grains are arranged in order of magnitude of grain diameter. The volume median diameter can be measured by laser diffraction method.
The present invention may employ sulfonanilide insecticidal/acaricidal compounds such as 2-methoxy carbonyl-4-chlorotrifluoromethanesulfonanilide, pyrethroidal compounds such as (S)-2-methyl-4oxo-3-(2-propynyl)cyclopent-2-enyl (1R)-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, tetramethrin, carbamate compounds such as metoxadiazone, neonicotinoids such as acetamiprid [(E)-N1-((6-chloro-3-pyridinyl)methyl)-N2-cyano-N1-methylacetamidine], nitenpyram [N-((6-chloro-3-pyridinyl)methyl)-N-ethyl-Nxe2x80x2-methyl-2-nitro-1,1-ethylenediamine], thiaclopid [(3-((6-chloro-3-pyridinyl)methyl)-2-thiazolidinylidene)cyanamide], thiamethoxam [3-((2-chloro-5-thiazolyl)methyl)-5-methyl-4-nitroiminotetrahydro-1,3,5oxadiazine], chlothianidine [1-(2-chloro-5-thiazolyl)methyl-3-methyl-2-nitroguanidine] and 1-(tetrahydrofuran-3-yl)methyl-3-methyl-2-nitroguanidine, etoxazole [5-tert-butyl-2-[2-(2,6-difluorophenyl)-4,5-dihydro-1,3-oxazol-4-yl]phenetole], and/or so on as the pesticidal ingredient. The amount of the pesticidal ingredients is generally 1% to 25% by weight based on the total amount of the present composition.
The present invention may employ various organic foaming agents, but an organic foaming agent wherein the heat decomposition thereof generates gas usually is employed. More specifically, an,organic foaming agent wherein the gas generated from thermal decomposition is nitrogen and wherein the foaming temperature is 300xc2x0 C. or less is usually employed. Azodicarbonamide; p-toluenesulfonylhydrazide; benzenesufonylhydrazide; p,pxe2x80x2-oxybis(benzenesulfonylhydrazide); azobisisobutyronitrile; 02,2xe2x80x2-azobisisobutyroamide; 2-(carbamoylazo)isobutyronitrile; methyl-2,2xe2x80x2-azobisisobutyrate; 2,4-bis(azosulfonyltoluene); 1,1xe2x80x2-azobiscyclohexanecarbonitrile; dinitrosopentamethylenetetramine, and so on are examples of possible organic foaming agents that may be employed for the present invention. The organic foaming agents thereof are generally employed as powdery material of about 50 to 200 mesh. The amount of the organic foaming agents is generally 10% to 97% by weight based on the total amount of the present composition.
The pesticidal ingredient and the organic foaming agent may be mixed in various methods to obtain the pesticidal composition, but it is preferable to mix the pesticidal ingredient and the organic foaming agent homogeneously to achieve a higher vaporization rate of the pesticidal ingredient. More specifically, after an appropriate amount of water is added to a mixture of the pesticidal ingredient and organic foaming agent, the mixture may be formed to granules wherein the granular diameter is 1 to 4 mm, preferably a granular diameter of 1.5 mm to 3 mm, and dried. The mixture preferably contains a temperature controlling agent and/or a binder described below.
Grinders/pulverizers such as a centrifugal grinder/pulverizer, jet mill, hammer mill, pin mill, ball mill and oscillating grinders/pulverizers may be utilized to break down the pesticidal ingredients into finer powder, so that the volume median diameter is 30 xcexcm or less.
The pesticidal composition may also comprise of fragrance materials; deodorants; synergists such as piperonyl butoxide, N-(2-ethylhexyl)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(2-ethylhexyl)-1-isopropyl-4-methylbicyclo[2.2.2]oct-5-ene-2,3-dicarboximide, octachlorodipropylether; and so on, in addition to the organic foaming agent and the pesticidal ingredient.
Furthermore, the temperature wherein the organic foaming agent is decomposed, may be controlled by incorporating temperature controlling agents such as zinc oxide, zinc carbide, urea, chrome yellow, carbon black, zinc stearate, and/or calcium stearate. Even further, uniform consistency or solidification may be improved by the incorporation of binder(s). Starch, natural polymers, synthetic polymers, and so on are examples of binders. Examples for the said natural polymers are tragacanth gum, gum arabic, guar gum, powdered gambier extraction, casein, and a mixture thereof. Examples for the said synthetic polymers are polyvinyl alcohol, polyacrylamide, sodium polyacrylate, polyethylene oxides, polyvinylpyrrolidone, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose salts, carboxymethylstarch salts, dialdehydestarch, cationic starches and a mixture thereof. The amount of the temperature controlling agent and binder is generally 0.1 to 10% and 0.1 to 5% by weight based on the total amount of the present composition respectively.
It is preferable that thermal decomposition of the organic foaming agent is accomplished by the heat of a chemical reaction. For example, the pesticidal composition may be placed in a container that is made of good heat conductivity, like metal, so the pesticidal composition may be heated through the said container. Once the pesticidal composition is heated to the appropriate temperature, the organic foaming agent is decomposed and generates gas and the pesticidal ingredient is blown down and vaporized into the environment.
More specifically, a device set forth in FIG. 1 may be utilized to heat the pesticidal composition. The pesticidal composition 1 is placed interior to the separating wall 4 wherein calcium oxide 3 is placed in a position that is exterior to the separating wall. An appropriate amount of water may then be poured to the calcium oxide through a water entrance 5 to cause the calcium oxide-water reaction that heats the pesticidal composition. Once the pesticidal composition reaches the appropriate temperature, the organic foaming agent will decompose and generate gas, and the pesticidal ingredient will be blown down and vaporized.